A Microsoft Windows policy loophole has been observed being exploited primarily by native Chinese-speaking threat actors to forge signatures on kernel-mode drivers.
"Actors are leveraging multiple open-source tools that alter the signing date of kernel mode drivers to load malicious and unverified drivers signed with expired certificates," Cisco Talos said in an
exhaustive two-part report shared with The Hacker News. "This is a major threat, as access to the kernel provides complete access to a system, and therefore total compromise."
Following responsible disclosure, Microsoft
said it has taken steps to block all certificates to mitigate the threat. It further stated that its investigation found "the activity was limited to the abuse of several developer program accounts and that no Microsoft account compromise has been identified."